Magnetic water-level indicator for steam-boilers.



P. W. MONTGOMERY. MAGNETIC WATER LEVEL INDICATOR FOB. STEAM BOILERS.

'AIPLIOATION FILED JULY 26, 1912. i

. Patented Feb. 16, 1915.

2 SHEETS-SHEET 1.

P. W. MONTGOMERY.

MAGNETIC WATER LEVEL INDICATOR FOR STEAM BOILERS.

APPLICATION FILED JULY 26, 1912.

Patented Feb.16,1915.

v 2 SHEETS-SHEET 2.

Hc9M Ci x: an time ra'rnr nitrite.

PERCY WILLIAM MONTGOMERY, F SYDNEY, NEW SOUTH WALES, AUSTRALIA.

iunenn'rrc wanna-LEVEL mmcaron roe STEAM-BOILERS.

weenie.

Specification of Letters Patent.

Application filedJuly 26, 1912. Serial Ito. 711,710.

certain new and useful Improvements in Magnetic Water-Level Indicators for Steam- Boilers, of which the following is a specifi cation.

The object of this invention is to obviate the use of the glass tubes commonly used in connection with steam boilers (communicating at their upper and lower ends respectively with the steam and water spaces within the boiler) to indicate visually the level of the surface of the water therein, and to .provide an indicator in which no material of a brittle nature is subjected to. pressure of water or steam.

It is well known that the usual glass tubes are liable to fracture under sudden changes of temperature or from other causes, with frequently disastrous results, but in my invention I provide a casing (communicating at its upper and lower portions respectively with the steam and water spaces of the boiler) which owing to the fact that it is unnecessary that the mechanism therein should" be visible, may-be made entirely of metal preferably of a non-oxidizable and non-magnetic middle within the casing and carrying a permanent bar-magnet so positioned longitudinally that its neutral axis is in line with the pivotal axis of the carrying arm and one end is in line with the center of the said-float. The other end of the said arm is provided with an adjustable counter-poise so that the balance of the arm and float may he regulated, it being essential for the proper working of the invention that the immersion of the float should be such that its center is level with the surface of the water.

The magnetic force of the bar-magnet is employed to operate or control synchronously with the movement of the float-arm. a magnetized needle or pointer mounted on the outside of the face of the casing upon a pivot in line with that of the float arm, and having its neutral axis coincident with its pivot.

The disposition of the magnet within the float-arm as regards the location of its poles is immaterial but on the principle that like poles repel and unlike poles attact the The apparatus when in use is positioned so that the normal or proper working level of the water is indicated by the pointer when in the horizontal position, any variation of level being indicated by upward or downward inclination thereof, the amount of such inclination being ascertained by the position of the pointer and by reference to a graduated dial in front of which the pointer moves.

T will now further describe my invention with reference to the accompanying drawings in which Figure 1 is a front perspective view of the apparatus. Fig. 2 is a perspective view of the back ofthe removable cover of the casing showing the internal parts. Fig. 3 is a sectional elevation of the apparatus. Fig. t is a sectional plan thereof. Fig. 5 is an interior view showing the normal position of the float-arm in full lines and inclined positions in dotted lines, the corresponding positions of the pointer being also shown in dotted lines. Fig. 6 is an external face view similarly showing the normal position and inclined position of the pointer and of the float arm. Fig. 7 illustrates the method of fitting the invention to ordinary gage-glass mountings, and Fig. 8 shows amodification of the arrangement of the float and float arm whereby the latter with the magnet is brought closer to the pointer.

The casing or float-chamber 10 is in comratemeareninmis. I

lines in Fig. 5. On theother munication with the steam and water spaces of the b iler by means of connections 11 and 12 respectively and is provided with a removable cover 13 carrying on its inner face a bracket 14. The non-corrosive and nonmagnetic float-arm 15 has at one end the float 16 having a central stop-plate 17 against which one end of the bar magnet 18 contacts, the other end of the said arm being fitted with the water-tight plug 19 which bears against the other end of the magnet and prevents longitudinal movement of the latter, which is made a neat sliding fit in the said arm or is packed therein so that its alinement with the center line of the same is assured. The float-arm is supported by pivots 20 and 21 projecting horizontally on opposite sides from the ring member 22, the former bearing in a socket in the adjusting set pin 31 of the bracket 14 and the latter in a socket in the cover 13 as shown in Fig. 4. Adjustment and regulation of the balance of the float-arm and float is effected by means of the adjustable counterpoise 23 for the purpose before stated.

' On the outside of the removable cover 13 is fitted a bracket 24 between which and the said cover is pivotally mounted the magnetized needle or pointer 25, its indicating end terminating in line with the center of the float, for obviously if it were not so it would give a false reading when the float arm is in an inclined position. The cover 13 has attached to it or inscribed upon it a dial having graduated markings 26. For the protection of the pointer an outer cover 27 of transparent material such as glass or mica is provided, secured in a ring flange 28 attached to the cover 13.

It is to be noted that it is necessary that the float arm should have a slight over-balance toward the float end to insure the latter following the surface of the water as the .level of the latter falls, but in the event of the rise or fall being abnormal the arm is prevented from assuming the vertical and possibly inoperative position by contacting with the bracket 14 as shown b the dotted and in the event of failure of the magnetic force to control the pointer this fact is made evident by the pointer assuming a truly vertical position. This is effected by providing 8."

cover may if considered desirable have their inner surfaces amalgamated with mercury to prevent corrosion.

In Fig. 7 illustrating the method of fitting the invention to ordinary gage-glass mountings, the steam and Water connections consist of ferrules 32 and 33 attached respectively to the top and bottom of the casing and adapted for insertion in the mountings 34 and 35 similarly to the ends of an ordinary gage-glass.

. In Fig. 8 it will be noted that the float arm 15 instead of being disposed centrally with the float 16, is attached more to the side of the latter toward the removable cover 13, thereby bringing the magnet 18 nearer to the pointer 25 so that the magnetic force of the latter is more effective, and space is economized.

What I claim is In a water level indicator for steam boilers, a steam and water tight casing having steam and water connections to the boiler, a tubular arm pivotally supported within said casing intermediate of its length and having one end thereof enlarged and forming a float, said tube being suitably sealed at the other end, a counter-poise adjustably arranged on one end of said tube, a bar magnet inclosed within said tube and protected from corrosion, a magnetized pointer plvotally secured to the outer face of the said casing in alinement with,the pivotal axis of said tubular arm and adapted to'follow the movement of the bar magnet through its magnetic influence, and a suitable casing inclosing said indicator pointer.

In testimony whereof I aflix my signature in presence of two witnesses.

. PERCY WILLIAM MONTGOMERY. Witnesses:

WM. NEWTON,

CHAS. HATTON. 

